This research involves both an epidemiological and an intervention study focusing on the risks and manifestations of AIDS among narcotic addicts. In the epidemiological study, baseline and followup examinations will be conducted with narcotic addict clients in a large methadone maintenance program in New York City. The epidemiological study will: 1) determine the prevalence, incidence, and cumulative incidence of testing positive for exposure to the HIV virus; 2) determine the prevalence, incidence, and cumulative incidence of morbidity and mortality due to AIDS; 3) identify risk factors associated with testing positive for HIV; and 4) determine the predictive utility of an addiction career typology (based on relative duration of addiction, nonaddiction, and incarceration) with respect to testing positive for HIV. Subsequent to a baseline evaluation of 1800 narcotic addicts, blood samples will be drawn every three months from all clients who previously tested negative for HIV. Blood test results (ELISA and Western Blot), morbidity/mortality information, and selfreport regarding AIDS related behavior will also be obtained at each of the 3month time points. Survival, density, and hazard functions will be computed. Comparisons, with respect to risk factors and typology, of individuals testing positive and negative for AIDS will be made utilizing multivariate analyses on both retrospective and prospective data. The intervention study, a controlled experiment utilizing a randomly selected subsample of 270 narcotic addicts from the larger population, will test the relative effectiveness of a clinically guided selfhelp approach in modifying behavior and attitudes associated with exposure to AIDS. In this 18month study, a selfhelp procedure will be compared to standard clinic treatment and standard clinic treatment plus a structured lecture series focusing on AIDS related topics. The usual drug abuse treatment criteria of effectiveness will be examined along with the AIDS related criterion measures. This proposal builds on prior work by this research team on the natural history of narcotic addiction and treatment intervention strategies.